There were 23 shell casings and 13 bullet fragments recovered from the lobby of 345 Park Avenue and 24 spent shell casings on the 33rd floor, police said.

A man stalked through a Manhattan office tower firing a rifle, killing four people, including a New York City police officer, and wounding a fifth before taking his own life, officials said.

This is a breaking news story. For latest updates, please go to our live blog. An NYPD officer and at least four other victims were killed in a shooting at an office skyscraper in midtown Manhattan Monday evening,